Using an Office-Based, Dedicated Extremity MRI Scanner for Depicting Important Structures in Common Wrist Pathologies: A Pilot Comparison with a Conventional MRI Scanner.

Background Compared with the conventional magnetic resonance imaging (MRI), dedicated MRI scanners are more accessible. Images of a dedicated 1.0-T MRI specifically developed for the hand and wrist were compared with images of a conventional 1.5-T MRI. Methods Paired images of the right wrist were randomized and separately graded by two experienced radiologists for the quality of anatomical details, including the triangular fibrocartilage complex, carpal ligaments, intercarpal cartilage, median and ulnar nerves, overall image quality, and artifacts. Interrater reliability was measured with the percentage of exact agreement and agreement within a range of ± 1 score point. Participant experience of undergoing the examination in both MRI scanners was evaluated using a questionnaire. Results The overall image quality of all sequences was considered to be moderate to high. In 25 of 38 paired images, no statistically significant difference was found between the MRI scanners. Ten scores were found to be in favor of the dedicated extremity MRI. Within a range of ± 1 score point, the extremity MRI and the conventional MRI demonstrated an interrater agreement of 67 to 100% and 70 to 100%, respectively. Among the respondents of the questionnaire, the extremity MRI scored better for participant satisfaction when compared with the conventional MRI. Conclusions In healthy volunteers, the dedicated extremity MRI generally is similar or superior to the conventional MRI in the depiction of anatomical structures of the wrists, image quality, and artifacts, and significantly scored better on participant satisfaction. Future clinical studies should focus on defining the diagnostic value of the extremity MRI in wrist pathologies.

Magnetic resonance imaging screening results compared with explantation results in poly implant prothèse silicone breast implants, recalled from the European market in 2010.

BACKGROUND: In a prospective cohort study, the authors followed 112 women whose Poly Implant Prothèse silicone breast implants were recalled. Magnetic resonance imaging results and clinical consequences were previously published. The authors compared magnetic resonance imaging screening with explantation results to study the diagnostic value of magnetic resonance imaging in this unique unselected and nonbiased group. METHODS ONE HUNDRED TWELVE: women with 224 proven Poly Implant Prothèse implants after a mean implantation time of 10 years were enrolled in 2011. All women underwent magnetic resonance imaging screening and were offered explantation. The explantation details of 107 women could be compared with magnetic resonance imaging results. RESULTS: Of 107 women, 29 (27 percent) had at least one ruptured implant at explantation, and 44 of 214 explanted implants (21 percent) were ruptured. The magnetic resonance imaging results correctly diagnosed 154 intact and 35 ruptured implants. Sensitivity and specificity were 80 percent and 91 percent, respectively. The positive predictive value was 69 percent, and the negative predictive value was 95 percent. CONCLUSIONS: The accuracy of magnetic resonance imaging is comparable to previously published data from other manufacturers of modern silicone implants but lower than that of some recent validation studies in selected symptomatic women. The authors believe that this study is representative of common daily practice as they followed normal day-to-day magnetic resonance imaging protocol without using multiple independent readers. The authors hope that this study will contribute to the ongoing discussion to screen asymptomatic women with modern silicone breast implants. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, II.

Discovertebral (Andersson) lesions in severe ankylosing spondylitis: a study using MRI and conventional radiography.

The objective of this study is to investigate the prevalence of Andersson lesions (AL) in ankylosing spondylitis (AS) patients who will start anti-tumor necrosis factor (TNF) treatment. Radiographs and magnetic resonance imaging (MRI) of the spine were performed before therapy with anti-TNF. ALs were defined as discovertebral endplate destructions on MRI, associated with bone marrow edema and fat replacement or sclerosis, a decreased signal on T1, enhancement after contrast administration (gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA)), and increased signal on T2 and short tau inversion recovery (STIR). Additionally, conventional radiography showed a fracture line, irregular endplates, and increased sclerosis of adjacent vertebral bodies. Fifty-six AS patients were included, 68% males, mean age of 43 years, and mean disease duration of 11 years. The mean bath ankylosing spondylitis disease activity index was 6.4, and 24% of all patients had ankylosis. Only one patient showed a discovertebral abnormality with bone marrow edema of more than 50% of the vertebral bodies adjacent to the intervertebral disk of T7/T8 and T9/T10, a hypodense signal area on T1, and a high signal on STIR. Irregular endplates were depicted, and T1 after Gd-DTPA demonstrated high signal intensity around the disk margins. However, no fracture line was visible on conventional radiology, and therefore, this case was not considered to be an AL. No AL was detected in our AS patients, who were candidates for anti-TNF treatment. One patient showed a discovertebral abnormality on MRI, without a fracture line on conventional radiology. The relative small proportion of patients with a long-established disease might explain this finding for, particularly, an ankylosed spine is prone to develop an AL.

The use of perfusion CT for the evaluation of therapy combining AZD2171 with gefitinib in cancer patients.

The purpose of this study was to determine the feasibility of dynamic contrast-enhanced perfusion CT (CTP) in evaluating the hemodynamic response of tumors in the chest and abdomen treated with a combination of AZD2171 and gefitinib. Thirteen patients were examined just before and every 4-6 weeks after starting therapy. Following intravenous injection of a contrast agent, dynamic image acquisition was obtained at the level of a selected tumor location. To calculate perfusion, the maximum-slope method was used. Pre-treatment average perfusion for extra-hepatic masses was 84 ml/min/100 g, for liver masses arterial perfusion was 25 ml/min/100 g, and a portal perfusion of 30 ml/min/100 g was found. After the administration of AZD2171 and gefitinib, in extra-hepatic masses an initial decrease in perfusion of 18% was followed by a plateau and in liver masses an initial decrease of 39% within the lesions and of 36% within a rim region surrounding the lesions was followed by a tendency to recovery of hepatic artery flow. In conclusion, CTP is feasible in showing changes of perfusion induced by anti-angiogenic therapy.

Factors affecting sensitivity and specificity of screening mammography and MRI in women with an inherited risk for breast cancer.

BACKGROUND: The MRISC study is a screening study, in which women with an increased risk of hereditary breast cancer are screened by a yearly mammography and MRI, and half-yearly clinical breast examination. The sensitivity found in this study was 40% for mammography and 71% for MRI and the specificity was 95 and 90%, respectively. In the current subsequent study we investigated whether these results are influenced by age, a BRCA1/2 mutation, menopausal status and breast density. PATIENTS AND METHODS: From November 1999 to October 2003, 1909 eligible women were screened and 50 breast cancers were detected. For the current analysis, data of 4134 screening rounds and 45 detected breast cancers were used. For both imaging modalities, screening parameters, receiver operating characteristic (ROC) curves and uni- and multivariate odds ratios (ORs) were calculated. All analyses were separately performed for age at entry (< 40, 40-49, > or =50), mutation status, menopausal status and breast density. RESULTS: Sensitivity of MRI was decreased in women with high breast density (adjusted OR 0.08). False-positive rates of both mammography (OR(adj) 1.67) and MRI (OR(adj) 1.21) were increased by high breast density, that of MRI by pre-menopausal status (OR(adj) 1.70), young age (OR(adj) 1.58 for women 40-49 years versus women > or =50 years) and decreased in BRCA1/2 mutation carriers (OR(adj) 0.74). In all investigated subgroups the discriminating capacity (measured by the area under the ROC-curve) was higher for MRI than for mammography, with the largest differences for BRCA1/2 mutation carriers (0.237), for women between 40 and 49 years (0.227) and for women with a low breast density (0.237). CONCLUSIONS: This report supports the earlier recommendation that MRI should be a standard screening method for breast cancer in BRCA1/2 mutation carriers.

Differences between first and subsequent rounds of the MRISC breast cancer screening program for women with a familial or genetic predisposition.

BACKGROUND: Within the Dutch MRI Screening (MRISC) study, a Dutch multicenter screening study for hereditary breast cancer, the authors investigated whether previously reported increased diagnostic accuracy of magnetic resonance imaging (MRI) compared with mammography would be maintained during subsequent screening rounds. METHODS: From November 1999 to October 2003, 1909 eligible women were included in the study. Screening parameters and tumor characteristics of different rounds were calculated and compared. The authors defined 3 different types of imaging screening rounds: first round in women never screened by imaging before, first round in women screened by imaging (mainly mammography) before, and subsequent rounds. RESULTS: The difference in sensitivity for invasive cancers between mammography and MRI was largest in the first round of women previously screened with mammography (20.0 vs. 93.3%; P=.003), but also in subsequent rounds, there was a significant difference in favor of MRI (29.4 vs. 76.5%; P=.02). The difference in false-positive rate between mammography and MRI was also largest in the first round of women previously screened with mammography (5.5 vs. 14.0%; P<.001), and it remained significant in subsequent rounds (4.6 vs. 8.2%; P<.001). Screen-detected tumors were smaller and more often lymph node negative than symptomatic tumors in age-matched control patients, but no major differences in tumor stage were found between tumors detected at subsequent rounds compared with those in the first round. CONCLUSIONS: In subsequent rounds, a significantly higher sensitivity and better discriminating capacity of MRI compared with mammography was maintained, and a favorable tumor stage compared with age-matched symptomatic controls. As results of these subsequent screening rounds were most predictive for long-term effects, the authors expect that this screening program will contribute to a decrease of breast cancer mortality in these high-risk women.

Effects of 10 years of growth hormone (GH) replacement therapy in adult GH-deficient men.

OBJECTIVE: GH-deficient adults have changes in body composition, bone mineral density (BMD) and lipid profile that can be altered by GH substitution. However, long-term data on GH substitution (up to 10 years of follow-up) are limited. DESIGN: The effects of 10 years of GH replacement therapy on BMD, body composition, bone parameters, serum lipids and glucose metabolism were studied. PATIENTS: Twenty-three childhood-onset GH-deficient men (mean age at baseline 28.6 years) were studied during 10 years of GH substitution therapy. A group of 19 age-matched healthy men served as a control group for BMD measurements at baseline and after 10 years. RESULTS: BMD of the lumbar spine increased during the 10 years of GH therapy. Bone markers and BMD in the hip increased during the first 5 years of GH therapy, but were not different from baseline after 10 years. BMD changes over time in the lumbar spine and femoral neck were significantly different in the patients compared to the controls. After 10 years the difference between the groups had decreased, but BMD was still higher in the controls than in the patients. Lipid profile had improved after 10 years of GH therapy, but body mass index (BMI), waist-hip ratio (WHR), fasting glucose and glycosylated haemoglobin (HbA1c) had increased compared to baseline. CONCLUSIONS: This long-term follow-up study found that 10 years of GH substitution in GH-deficient men causes sustained improvements in BMD in the lumbar spine and lipid profile but not in body composition.

Efficacy of MRI and mammography for breast-cancer screening in women with a familial or genetic predisposition.

BACKGROUND: The value of regular surveillance for breast cancer in women with a genetic or familial predisposition to breast cancer is currently unproven. We compared the efficacy of magnetic resonance imaging (MRI) with that of mammography for screening in this group of high-risk women. METHODS: Women who had a cumulative lifetime risk of breast cancer of 15 percent or more were screened every six months with a clinical breast examination and once a year by mammography and MRI, with independent readings. The characteristics of the cancers that were detected were compared with the characteristics of those in two different age-matched control groups. RESULTS: We screened 1909 eligible women, including 358 carriers of germ-line mutations. Within a median follow-up period of 2.9 years, 51 tumors (44 invasive cancers, 6 ductal carcinomas in situ, and 1 lymphoma) and 1 lobular carcinoma in situ were detected. The sensitivity of clinical breast examination, mammography, and MRI for detecting invasive breast cancer was 17.9 percent, 33.3 percent, and 79.5 percent, respectively, and the specificity was 98.1 percent, 95.0 percent, and 89.8 percent, respectively. The overall discriminating capacity of MRI was significantly better than that of mammography (P<0.05). The proportion of invasive tumors that were 10 mm or less in diameter was significantly greater in our surveillance group (43.2 percent) than in either control group (14.0 percent [P<0.001] and 12.5 percent [P=0.04], respectively). The combined incidence of positive axillary nodes and micrometastases in invasive cancers in our study was 21.4 percent, as compared with 52.4 percent (P<0.001) and 56.4 percent (P=0.001) in the two control groups. CONCLUSIONS: MRI appears to be more sensitive than mammography in detecting tumors in women with an inherited susceptibility to breast cancer.

Lung density measurements in spontaneous pneumothorax demonstrate airtrapping.

PURPOSE: Idiopathic spontaneous pneumothorax (SP) is the result of leakage of air from the lung parenchyma through a ruptured visceral pleura into the pleural cavity. This rupture is thought to be caused by an increased pressure difference between parenchymal airspace and pleural cavity. We hypothesize that rather peripheral airway inflammation leads to obstruction with check valve phenomena and by that to airtrapping in the lung parenchyma, which precedes spontaneous pneumothorax. SETTING: University hospital. MATERIALS AND METHODS: Forty-one matched healthy volunteers (21 smokers and 20 nonsmokers), and 41 patients with SP (21 patients with and 20 patients without bullae) underwent spirometrically controlled high-resolution CT density measurements with automatic contour tracing at 10% and at 90% of vital capacity. RESULTS: Patients with SP showed lower mean lung density (MLD) values and higher percentages of Hounsfield units (HU) below - 900 HU (pixel index [PI]) compared to the healthy volunteers on expiratory scans. This enhanced airtrapping phenomenon is seen in both the SP lung (MLD, p = 002; PI, p = 0.01) and the contralateral lung (MLD, p = 0.009; PI, p = 0.05) compared to the control subjects. The difference with control subjects is independent of smoking behavior and bullae. CONCLUSIONS: Peripheral airway obstruction with airtrapping was found, and it is supposed to play an important role in the pathogenesis of spontaneous pneumothorax.

Variations in diagnostic performances of dual-energy X-ray absorptiometry in the northwest of The Netherlands.

Between-center variation in bone densitometry may influence the frequency of the diagnosis of osteoporosis. To evaluate this problem, dual-energy X-ray absorptiometry (DXA) machines of the medical centers in the northwest of The Netherlands were evaluated. Four phantoms were used to test the 17 DXA machines of 16 participating centers. Each phantom was measured 10 times and the data were analyzed on the corresponding DXA machine using the software delivered by the manufacturer. The analyses were done with the reference population as used in daily practice. There were DXA devices of seven different brands and types, using four different reference populations for the lumbar spine and seven for the hip. The observed differences in bone mineral densities (BMD) were up to 0.20 g/cm(2) for the lumbar spine, 0.15 g/cm(2) for the femoral neck, and 0.12 g/cm(2) for the total hip. The coefficients of variation (CV) of the repeated phantom measurements ranged between 0.3% and 1.3% for the lumbar spine, 1.6% and 4.6% for the femoral neck, and 0.3% and 0.9% for the total hip. The mean female T-scores of 10 phantom measurements differed up to 0.6 SD between the DXA machines for the lumbar spine and up to 0.8 SD for the total hip. Mathematically, replacing a Hologic 2000 DXA machine with a newer type of the same brand (a Hologic 4500) caused a shift in diagnosis from osteoporosis to osteopenia of +1.1% for the lumbar spine and -4.5% for the total hip. When the Hologic 2000 was replaced by a Hologic 4500 with NHANES reference values, the shift from osteoporosis to osteopenia was also +1.1% for the lumbar spine, and -13.4% for the total hip. The clinical impact of the observed differences is difficult to estimate. One may conclude that the differences of the tested DXA devices are partly based on differences in DXA machines, but for the most part on the use of different reference populations. It is recommended to standardize the reference population, although the consequent shift in diagnosis will be confusing for physicians and patients, and adaptation of the reference values on the DXA devices of different brands with different technical qualities and measurement specifications will be difficult.

Cine MRI assessment of aortic aneurysm dynamics before and after endovascular repair.

PURPOSE: To evaluate stent-graft and aneurysm wall motions during the cardiac cycle using cine magnetic resonance imaging (MRI) to identify mechanisms of long-term failure of endovascular aneurysm repair (EVAR). METHODS: Prior to and after EVAR in 7 patients with abdominal aortic aneurysms (AAA), 12 MRI images per cardiac cycle were acquired in transverse, sagittal, and coronal planes of the aneurysm. Two independent observers blinded to the aim of the study manually traced stent-graft and aneurysm wall contours. Translation was defined as the maximal displacement of the contours in the peak-systolic image compared to the end-diastolic image. Aneurysm wall motions before and after repair were compared. Stent-graft and aneurysm configuration changes during the cardiac cycle were evaluated. The relation between translation and the degree of angulation of the stent-graft was calculated. RESULTS: The anteroposterior translation of the aneurysm decreased from a median 1.05 mm (range <0.5-1.29) before EVAR to within pixel size (<0.5 mm) after EVAR (p=0.04). The cranial-caudal translation of the aneurysm increased from a median 1.01 mm (range <0.5-1.51) before to 1.69 mm (range 1.1-1.99) after EVAR (p=0.02). In 4 stent-grafts, bending during cardiac systole was observed at the site of maximal angulation of the device. In transverse sections, 2-dimensional pulsatile wall motion of the aneurysm was 0.25 cm(2) (range 0.07-0.29) before and 0.17 cm(2) (range 0.07-0.42) after EVAR (p=0.79). No pulsatility of the stent-graft itself was observed. The correlation coefficient between angulation of the stent-graft and the increase in cranial-caudal translation after EVAR was 0.67 (p>0.05). CONCLUSIONS: After EVAR, increased longitudinal translation of both the aneurysm and stent-graft was observed, indicating downward pulling forces at the proximal fixation site. Secondly, increased bending was seen at the site of maximal angulation, which implies a risk of metal fatigue and fabric damage at sites of stent-graft angulation.

Lung attenuation measurements in healthy young adults.

BACKGROUND: High-resolution computed tomography (HRCT) attenuation measurements may be more sensitive in finding early emphysematous changes in relatively young subjects than lung function measurements. OBJECTIVES: To define lung attenuation parameters in smokers and never-smokers. METHODS: A prospective comparative study in a university hospital setting was designed with 20 healthy smoking and 20 nonsmoking volunteers. Attenuation measurements on spirometrically controlled HRCT at three levels in the upper half of the lungs at 10% and 90% of vital capacity (VC10% and VD90%) were done, and lung function measurements were performed. RESULTS: Mean lung attenuation (MLD) and pixel index (PI) were correlated with lung function and smoking history. Small attenuation differences in the left and right lung were found but no sex-related differences. At main carina (MC) level, the PI was higher at VC90% (p < 0.0001) but lower at VC10% (p < 0.01) compared to the apex. Age correlated with attenuation parameters at VC10%, whereas for pack-years no correlation was found. There were attenuation correlations with VC (PI: R = 0.31, p < 0.05 at VC10%/90%), residual volume (MLD: R = -0.31, p < 0.05 at VC10%), and total lung capacity (PI: R = 0.31, p < 0.05 at VC10%/VC90%). CONCLUSIONS: Lung attenuation during inspiration was lower at the MC level than at the top, but higher on expiratory scans. No sex-related differences were found. Lung attenuation decreases with age on expiratory scans. This seemed to be of more importance than the amount of pack-years of smoking. A relationship with lung function parameters is not uniformly proven.

Measuring secondary deformities of the shoulder in children with obstetric brachial plexus lesion: reliability of three methods.

In this study the interobserver reliability of three established measurement methods to objectify secondary deformities of the shoulder in obstetric brachial plexus lesion was evaluated (OBPL). Magnet resonance imaging scans of 30 affected shoulders of 29 OBPL children, mean age 1 year 9 months (range 3 months to 6.3 years) were used. The reliability of the measurement of glenoid version had a standard deviation of differences of measurements between 5.4 and 5.9 degrees. The reliability of the glenoid form showed a kappa value between 0.52 and 0.64, and the reliability of the humeral subluxation had a standard deviation between 7.7 and 12.4 degrees. The measurement methods showed no systematic bias.

Alternative approach to massive gastrointestinal bleeding in ulcerative colitis: highly selective transcatheter embolization.

Massive haemorrhage in ulcerative colitis mainly occurs as a result of exacerbated disease, usually acute or even fulminant colitis. Emergency proctocolectomy is currently advocated as the only reliable treatment of this patient group. However, this type of surgical intervention has a high rate of morbidity and mortality. Recently, several promising studies have been published that describe transcatheter embolization for the treatment of massive lower gastrointestinal bleeding in cases of bleeding colonic diverticular disease and angiodysplasia. Success rates of 48-88% have been reported. To avoid the high risk associated with emergency colectomy, this modern procedure was performed in an ulcerative colitis patient with intractable lower gastrointestinal bleeding. To our knowledge, this is the first patient with ulcerative colitis presenting with massive lower gastrointestinal blood loss to be successfully treated by highly selective transcatheter embolization. This interventional procedure is suggested as an alternative therapeutic approach to haematochezia in selected ulcerative colitis patients.

Assessment of patency of the internal jugular vein following neck dissection and microvascular flap reconstruction by power Doppler ultrasound.

The objective of this study was to assess patency of the internal jugular vein following modified radical or selective neck dissection and microvascular flap reconstruction by power Doppler ultrasound and its impact on free flap survival. In 23 patients who underwent selective or modified radical neck dissection and microvascular flap reconstruction the patency of the internal jugular vein was examined by power Doppler ultrasound on the first post-operative day and after follow-up of at least four months. On the first post-operative day in one patient partial thrombosis was found, while in the other 22 patients the internal jugular vein was normal patent. During follow-up in 17 (74 per cent) patients a normal patent internal jugular vein was found, while partial and complete thrombosis were found in three (13 per cent) patients each. On the first post-operative day 22 of the 23 (96 per cent) free flap veins were visualized. There was no free flap loss during follow-up. Power Doppler ultrasound is a valuable diagnostic technique for determination of internal jugular vein patency and may be useful as screening method or in case of clinical suspicion of thrombosis to determine internal jugular vein patency. Late internal jugular vein thrombosis may probably not effect free flap survival due to neovascularization.

Endovascular repair of a type B aortic dissection with transposition of a coexistent aberrant subclavian (lusorian) artery.

PURPOSE: To report the endovascular treatment of a relatively uncommon entity: an aortic type B dissection combined with an aberrant subclavian artery (SA). CASE REPORT: A 59-year-old patient was admitted with chest pain and interscapular back pain. A transesophageal ultrasound and magnetic resonance angiography revealed a type B aortic dissection originating at the level of an aberrant SA orifice. After failure of medical therapy, the dissection was treated by transluminal implantation of an Excluder stent-graft covering the entry site of the dissection at the aberrant SA orifice. Prior to the endovascular procedure, a transposition of the aberrant SA to the right carotid artery was performed through a supraclavicular approach. The patient remains asymptomatic at 19 months after the endovascular repair. CONCLUSIONS: Endovascular repair of a type B aortic dissection in the presence of a lusorian artery appears to be a feasible, safe, and less invasive alternative to conventional surgery. The need for concurrent transposition of the SA remains to be determined.

Magnetic resonance imaging of injected silicone: findings in seven male-to-female transsexuals.

Our goal was to describe the MR findings of subcutaneously injected silicone in male-to-female transsexuals and to determine the most optimal combination of pulse sequences for discrimination of injected silicone from the surrounding structures. Seven male-to-female transsexuals were referred for MRI in order to detect the injected silicone in the subcutaneous tissues and to visualize distant migration and possible complications. Conventional spin-echo (SE) T1-weighted and turbo SE proton-density/T2-weighted, plain short tau inversion recovery (STIR), and two STIR sequences with, respectively, water and silicone suppression were applied at 1.5 T. Three observers trained in MRI analysed the images separately for the abnormalities and rated the images using a four-level scale. The STIR with water suppression provided the highest contrast between silicone and the surrounding adipose tissue. Silicone-specific STIR pulse sequences provided clear images for the evaluation of the amount and patterns of local and distant spread of injected fluid silicone. Magnetic resonance imaging readily identifies the subcutaneously injected silicone, its distant migration and the amount of tissue disorganization around the silicone deposits. Two silicone-specific STIR sequences are usually sufficient for imaging the spread of silicone.